The Lappeenranta Sandcastle will be erected for the 16th time on the fortress headland. The annually changing themes for the Sandcastle have included Finnish castles, space, a jungle and sea adventures to name a few. More than three million kilos of sand is used to build the Sandcastle. This summer, we will celebrate 370 year old Lappeenranta at the Sandcastle and you can become interested in mathematics there and learn something new. The Sandcastle area is open from 8 June to 1 September 2019, and it features a café, an ice cream stand, rides and other activities. The street train route begins and ends at the Sandcastle. The street train offers guided tours in five languages: Finnish, English, German, Russian and Chinese.